Gun with detachable barrel mounting

ABSTRACT

A rifle has a barrel which is mounted detachably in the housing in that pairs of clamping rings ( 11, 12 ) are provided between the rear part of the barrel ( 5 ) and the inner cylindrical surface ( 3 ) of the housing ( 1 ), which clamping rings ( 11, 12 ) have mutually facing conical surfaces and are pressed axially by a clamping nut ( 13 ) against a collar ( 7 ) on the barrel ( 5 ). Such a barrel mounting can also be used for a housing made of light alloy, with simple production and with production-dependent tolerances and alignment errors being eliminated.

BACKGROUND OF THE INVENTION

The invention relates to a rifle having a barrel which is mounteddetachably in the light-alloy breech housing, the rear part of thebarrel being surrounded by an inner cylindrical surface of the breechhousing. Particularly in the case of repeater rifles, shrink joints orscrew connections are normally used to connect the barrel and the breechhousing. Shrink joints can be detached only with great difficulty, whilescrew connections are costly to manufacture. However, above all, screwconnections are not suitable for breech housings made of aluminum orlight alloys.

In such cases, clamping structures by means of a clamping screw ortransverse bolt arranged tangentially in the breech housing are used.However, these require breech housing extensions which are difficult tomanufacture and/or weakening longitudinal slots and, furthermore, havethe disadvantage of play, resulting from manufacturing tolerances,between the barrel and the housing bore, so that exact alignment of thebarrel axis and the housing longitudinal axis is not ensured.

GB 2142125 A admittedly discloses the use of clamping elements forconnecting two coaxial surfaces. However, this relates to the jointbetween a barrel liner and a main barrel which surrounds the latter and,of course, is also composed of steel. The barrel liner is fitted fromthe rear into a cartridge chamber which has conical wall parts. Theclamping elements, which are not slotted, surround an intermediatesleeve which is screwed onto the barrel from the rear, but withouttightening the clamping elements. Grubscrews distributed on thecircumference are provided for this purpose.

The aim of the present invention is to provide a barrel mounting whichavoids these diadvantages and which can also be used for a light-alloybreech housing, with simple production and with production-dependenttolerances and alignment errors being eliminated.

SUMMARY OF THE INVENTION

According to the invention, the foregoing is achieved by at least oneexternally cylindrical elastic clamping element, which is slotted in thelongitudinal direction and is axially loaded by a clamping nut that isarranged in front of the clamping element and is screwed to a thread onthe barrel, being provided between the rear part of the barrel and theinner cylindrical surface of the breech housing.

The clamping elements are mass-produced standard parts and are thus verytightly toleranced but nevertheless cheap, so that very accuratecentering is possible. On the outside, they rest against the cylindricalinner wall of the breech housing over a large area so that a reliablefriction lock can be achieved with a relatively low load on the breechhousing. Since the breech housing does not need any slots or expansionsfor this purpose, it can be produced easily from light alloy. The threadfor the clamping nut on the barrel can absorb considerable forces, sincethe barrel is actually composed of a material which is hardened orheat-treated. The nut is also composed of a high-strength material andthus occupies very little space and is accessible from the front.

In one possible embodiment, the rear part of the barrel has a conicalouter surface, and the clamping element is a clamping sleeve which isslotted alternately from the front and rear. Such clamping sleeves areknown in machine tools for clamping workpieces having a central bore.They are likewise cheap and very accurate standard parts, withaccurately known characteristics, and are particularly simple to fit.

In one preferred embodiment, pairs of clamping rings having mutuallyfacing conical surfaces are arranged between the clamping nut and acollar on the barrel. The friction force and the stress on the breechhousing from the inward pressure exerted by the clamping rings caneasily be matched to the respective requirements by choosing the numbersof pairs of rings and their coning angle. The collar allows the barrelto be accurately fixed axially.

In particular cases, it is advantageous, for safety, to provide aholding claw as well, which engages through an opening in the housinginto a recess or circumferential groove in the barrel. The simple shapeof the housing allows such an opening to be incorporated easily, withouthaving to weaken the cross section of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in the following text with reference tofigures, in which:

FIG. 1: shows a horizontal section through a part of a first embodimentof a rifle provided with the invention,

FIG. 2: is as FIG. 1, but showing a second embodiment.

DETAILED DESCRIPTION

FIG. 1 shows a part of the housing, which is denoted by 1. A rear innerwall 2 of smaller diameter represents, for example, the guide for a boltaction (not shown). Adjacent to this, there is a cylindrical innersurface 3 which has a larger diameter and extends forward to the fronthousing end, which is not illustrated in more detail. Arranged in frontof the guide 2 for the breech, there is a space 4 for a locking bush,not shown, which could be screwed to the rear end of the barrel.

A barrel 5 is mounted inside the housing 1, in a manner according to theinvention. Only its rear part is shown. A thread which is matched to therear part of the barrel 5 starts at 6 and extends as far as necessary tothe rear, but preferably not as far as a radial annular surface 8 of acollar 7. This collar 7 has a circumferential groove 9, for a purposewhich will be described later. The collar 7 can then also be followed bya cartridge chamber wall. The essential features are the thread 6 on thebarrel and the collar 7, as well as the cylindrical inner surface 3 ofthe housing.

In a first embodiment a plurality of clamping rings 11 and an equalnumber of clamping rings 12 are now provided in order to connect therear part of the barrel 5 to the housing 1. The clamping rings 11 areslotted, so that they can easily be expanded radially. Their outerenvelope surface is cylindrical and their inner envelope surface isconical. The respectively complementary rings 12 may be slotted, have acylindrical inner surface, and have a conical outer surface at the sameangle as the rings 11. The number of such pairs of rings can be chosenin accordance with the requirements. Adjacent to this at the front thereis a clamping nut 13 which can be screwed onto the thread 6 of thebarrel 5 and presses the clamping rings 11, 12 against the annularsurface 8 of the collar 7. In the process, the clamping rings 11 expand,with their cylindrical surfaces being pressed against the cylindricalsurfaces of the barrel and housing. They produce a friction-locked jointwhich is fixed and accurate both with respect to the barrel and withrespect to the housing. At the front, the clamping nut 13 also hasrecesses 14 for a pipe wrench, and can be secured by means of a threadedpin 15.

Finally, a bearing block 16 is also shown on the outside of the housing1, to which a holding claw 17 is screwed. This holding claw 17 engagesthrough an opening 18 in the housing 1 into the groove 9 in the collar7.

FIG. 2 shows another embodiment, in which identical parts have the samereference symbols. This differs from the previous embodiment in that aclamping sleeve 20 is provided instead of the pairs of rings 11, 12.This clamping sleeve is constructed in the manner known from arbors inmachine tool construction: it has slots 21, 22 which are positionedalternately from the front and rear over a large portion of its length,giving it the capability to expand radially, and has a conical innerwall 23, which is seated on a likewise conical outer surface 24 of thebarrel. Instead of pushing it against a stop, the clamping nut 13 pushesit onto the conical outer surface of the barrel 24 and, in the process,causes it to expand. Once again, this produces a firm friction-lockedjoint.

What is claimed is:
 1. A rifle comprises: a light-alloy breech housing having an inner cylindrical surface; a barrel having a rear part detachably mounted in the inner cylindrical surface of the housing along a longitudinal axis wherein a portion of the rear part is threaded; at least one elastic clamping element located on the rear part of the barrel between the barrel and the inner cylindrical surface of the housing, the at least one elastic clamping element having at least one slot extending in the direction of the longitudinal axis; and a clamping nut threaded on the threaded portion of the barrel for axially loading the at least one elastic clamping element for fixedly securing the barrel in the housing against axial movement.
 2. A rifle according to claim 1 wherein a further portion of the rear part of the barrel has a conical outer surface, and the at least one clamping element is a clamping sleeve which has at least two slots alternately on the front and on the rear and has a conical inner wall.
 3. A rifle according to claim 2 wherein a holding claw engages a groove in the barrel through an opening in the breech housing.
 4. A rifle according to claim 1 wherein the at least one clamping element comprises a pair of clamping rings having mutually facing conical surfaces arranged between the clamping nut and a collar on the barrel.
 5. A rifle according to claim 4 wherein a holding claw engages a groove in the barrel through an opening in the breech housing. 